Beam trammel



Jan. 23, 1951 c, J, OROURKE 2,539,097

BEAM TRAMMEL Filed July 7, 1944 2 Sheets-Sheet 1 INVENTOR.

Carl J. URU urke l951 I c. J. O'ROURKE 2,539,097

BEAM TRAMMEL Filed July '7 1944 2 Sheeisheet 2 I 11/1 Ill/II/IA IINVENTOR.

Cal-Ti URourke Patented Jan. 23, 1951 UNITED STATES PATENT OFFICE BEAMTRAMMEL Carl J. ORourke, Mount Vernon, Ohio Application July'7, 1944,Serial No. 543,864

1 claim. 1

This invention relates to improvements in trammels.

The primary object of this invention is the provision of a trammelembodying an improved beam construction and improved means foradjustably and efiiciently mounting point carrying fixtures thereon.

A further object of the invention is the provision of an improvedtrammel which is relatively light in weight, yet which is strong anddur- 1..

.able, has .a neat appearance, and one which has a wide range ofadjustment of the point carrying appliances upon the supporting beam.

A further object of this invention is the provision of improved meansfor adjustably mounting point carrying appliances upon the beams oftrammels, beam compasses and other like devices.

A further object of this invention is the provision of improved meansfor mounting an extension beam upon a trammel.

Other objects and advantages of the invention will be apparent duringthe course of the following detailed description.

In the accompanying drawings, forming a part of this specification andwherein similar refer- .ence characters designate corresponding partsthruout the several views,

Fig. 1 is a side elevation of the improved trammel.

Fig. 2 is a fragmentary cros sectional view showing improved means formounting an extension beam upon the main beam of a trammel or beamcompass.

Fig. 3 is an end view showing the end structure of the extension beam.

Fig. 4 is an end view showing the structure .of the end of the main beamwhich receives the extension beam.

Fig. 5 is across sectional view taken substantially on the line 55 ofFig. 1 and showing an improved construction of a point carrying, fixtureor appliance.

Fig. 6 is a cross sectional view similar to Fig. .5, but showing amodified form oi point carrying fixture or appliance.

Fig. 7 is a fragmentary cross sectional view showing the constructionbycmeans of which a ipoint carrying fixture or appliance ismounted upona beam, for fine adjustment.

Fig. '8 is a cross sectional view showing the manner in which a pointcarrying fixture or appliance may be mounted for efiicient quick slidingadjustment upon a beam.

In the drawing-s. wherein iorthenurpose of zilforms of the invention,the letter A may generally designate the .improved trammel. It mayinclude a main beam B adapted to receive an improved point carryingfixture or appliance C for coarse adjustment thereon, anda-pointcarrying fixture or appliance ,D for fine adjustment thereon. Anextension beam F may be provided for attachment by improved means G tothe main beam B. In lieu of the coarse adjustment point carrying fixtureor appliance C, I may employ a modified form C shown in Fig. 6.

It is the principal purpose of this invention to provide a relativelylight, durable and economical beam construction. :To that end the mainbeam B is preferably tubular and of metal or other suitable material. Incross section it is preterably circular.- The-wall thickness is justsufficieint to preserve the desired rigidity thereof and its passagewaymay extend from end to end. Other features of this main beam will be setforth in describing the application thereon of the point carrying legsor fixtures C and D.

Referring to. the point carrying fixture or leg C, the same is bestshown in Figs. 1, 5 and .8 of the drawings. It'inc ludes a tapered bodyportion .15 having a suitable socket '(not shown') at its lower end forreceiving a point l6. Broadly the term point :may designate a steelpointer, pencil, pen or any other device usually associated withtrammels, beam compasses and the like. The point 'I 6 is, of course,removable and may be held in place by any approved means such as a setscrew l1.

At its upper end the body portion 15 is bifurcated to provide upwardlyextending portions 2| and 22 suitably spaced to provide a socket 2B fordetachably receiving the beam B. The portion 2| may have a screwthreaded opening 23 therethru and the other portion 22 is provided withan aligning passageway 24. ,A look screw '38 may be provided, rotatablymounted :freely in the opening 24 and screw threaded in the opening 23,as shown in Fig. -8. The knurledhead of the screw 30 is provided forgrasping in the hand of the user in order to tighten the point carryinglegs C in fixed position upon the beam. The point carrying fixture orleg C has a coarse ad- .iustment upon the beam, since the adjustment iseffected merely by loosening the screw '30 and sliding the fixture alongthe beam. To prevent turning movement of the point carrying fixture Cupon the beam, as it is adjusted therealong, and-t maintain it 'in truealignment with the diusting fixture-D, :1 preferably inro- ..lustrationare shown preferred, and nodifie'd de a-tshaliow groove 35 along thebeam, in any suitable position thereon, preferably along one or theother of the sides. In cross section it is arcu ate. The groove 35receives a roller-shaped key 31 suitably positioned for rotation in asocket 38 provided in a side of the body I5, as shown in Fig. 8. Thesocket 38 may be elongated if desired. A leaf spring 40 is anchored atAl upon one of the bifurcations of the body l5, having its free endengaging the roller or key 31 for the purpose of urging the same intothe groove 35. The socket 38 is peened over at its inner end to preventpushing of the detent roller 3? out of the socket should the pointcarrying fixture be removed from the beam B. This provides a very strongand durable construction and one in which the spring action is such asto insure the maintenance of the roller key in the groove. The key 31may assume a ball shape if so desired, and it is immaterial whether thesame is placed upon the head side of the screw 30 or opposite thereto.The slot 35 extends from the point of application of the point carryingleg or fixture D to the extreme other end of the main beam B, whence itcontinues along the beam extension F, if the latter is used.

In the modified form of point carrying leg C, the slot 50 defining thebifurcations at the top of the body 15 may be placed at an acute angleto the vertical. Thus the leg may receive a finger engaging handle 5|,as shown in Fig. 6. Otherwise the structure is identical with that abovedescribed.

Referring to the point carrying fixture or leg construction D, for fineadjustment, the same includes a body portion (50 having at its lower enda set screw 6 la for clamping a suitable point 63 in the body 60. Ofcourse the point 63 may be a steel needle, pencil or pen or any otherpoint usually associated with trammels.

At its upper end the body 60 is bifurcated, providing leg portions 6|one of which is transversely apertured and the other screw threaded forreceiving a lock screw 62, shown in Fig. l, in the identical mannerprovided for the point carrying fixture C. The body 65 is socketed toreceive therein the end of the main beam B, and the screw 62 is merelyused for the purpose of tightly clamping the fixture D in place upon themain beam.

The point carrying fixture D has a very fine sliding adjustment alongthe beam B. To prevent turning movement of the appliance D upon thebeam, I provide a key pin 65, which is driven into the beam B. It has anend radially and slidably projecting into a groove 66 provided in thebody 60. This mounting of the pin 65 prevents turning movement of theleg or body 6% upon the beam, as is quite obvious. The body 60furthermore includes an externally screw threaded sleeve portion 19,which is not split; the slot providing the bifurcations 6i terminatingshort thereof. The externally screw threaded sleeve 10 is of a size tocomfortably and slidably receive the beam B. It may be of any lengthdesired and in this respect it is to be noted that it provides a verylong bearing mounting of the fixture D upon the beam.

In order to insure fine adjustment of the leg D upon the beam, I providea rotatable adjusting sleeve or nut mounted by means to be subsequentlydescribed upon an end of the beam. It is internally screw threaded at Itfor receiving the threads of the sleeve extension 7D. The adjusting nut75 is rotatably mounted against longitudinal movement upon the beam B bymeans of a plug which is force driven into an end of the beam B and heldtherein against turning by the pin 65 above described. This plug 89 hasan end extending beyond the end of the beam provided with an axial screwthreaded opening 83 adapted to receive the threaded shank of a screw 84.The latter has an enlarged head and receives a washer 86. Spaced fromthe washer 86 is an annular flange 87 formed integral with the plug 3B.The space between the flange 81 and washer 86 is sufficient to receivetherein the head portion 88 of the adjusting nut 15, so as to permit thefree rotation of the nut upon the plug 80 without binding action, andwithout any end play of the adjusting nut '57 With this construction itis obvious that upon rotation of the nut 15 the point carrying fixture Dwill be moved along the beam in either direction desired to efiect afine adjustment of the pointer D upon the beam. The nut 15 may beexternally knurled.

Referring to the improved means for mounting an extension beam F uponthe main beam B, the latter at its end opposite the fixture D is openand provided with a short integral segment 90, best shown in Figures 2and 4 of the drawings. This defines a fiat surface 9|.

The extension beam F is tubular and has a mounting plug 92 force fittedor held by means of a diametrically disposed pin 93 in an end thereof.The plug 92 beyond the extreme end margin of the extension beam F has anextension 95 of segmental cross section, and of a nature to fit in theopening 91 in the end of the beam B. This segmental extension 95 isprovided with a fiat surface 9'! adapted to contact the flat surface 9|of the main beam B. With this construction it is obvious that the beamsB and F may be connected so as to prevent relative rotation' In order tosecure the beams in close abutting relation, and to hold such position,extension portion 95 of the plug 92 is provided with a transverse screwthreaded socket 98 adapted to receive a set screw 99. The latter israther shallow and bites into the segment 50 to secure the beams B and Fin proper alignment. The beam B is provided with a suitable opening 99to permit of the extension of a screw driver or like too] into the screwthreaded passagewa 98 for access to the set screw 99.

From the foregoing it is apparent that an improved trammel has beenprovided which is light and durable in construction and one in which thepoint carrying fixtures are efiiciently mounted for ease and fineness ofadjustment. In particular the ball and groove connection of the fixtureC enables a smooth and eflicient action of this fixture upon the beamand of course the spring will prevent any play or looseness of mountingof the fixture C upon the beam, while at the same time permitting freeand efiicient coarse adjustment of the same upon the beam. It is to beunderstood that features of this invention may be used in connectionwith any type of trammel, such as a beam compass, ellipsograph or thelike.

Various changes in the shape, size and arrangement of parts may be madeto the form of invention herein shown and described without departingfrom the spirit of the invention or scope of the following claim.

I claim:

In a trammel structure the combination of an elongated beam having astraight groove inwardly of the external surface thereof extendingcompletely along the beam from end to end; a point carrying fixtureslidable upon said beam, means for clamping said point carrying fixtureagainst movement along the beam, and resilientl urged means carried bysaid point carrying fixture slidably extended into frictional engagementwith the beam within the groove and preventing turn-- ing movement ofthe point carrying fixture upon said beam, a second point carryingfixture slidably mounted upon the beam adjacent one end thereof, meanscarried by the beam and second point carrying fixture to prevent turningmovement of the second point carrying fixture upon the beam andpermitting limited sliding movement of the second mentioned fixturealong the beam, said second mentioned fixture having an externally screwthreaded sleeve thereon projecting in the direction of the adjacent endof the beam and surrounding the beam, and a nut rotatably carried bysaid beam at said end against 2 movement therealong threaded upon thescrew threads of said sleeve for movement of th second mentioned fixturealong the beam upon rotation of said nut.

CARL J. OROURKE.

6 1 REFERENCES CITED The folowing references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 336,868 Pratt Feb. 23, 1886617,014 Hannah 1 Jan. 3, 1899 813,095 Hottman Feb. 20, 1906 972,106Hannan Oct. 4, 1910 1,001,433 Olson Aug. 22, 1911 1,007,424 BjorklundOct. 31, 1911 2,178,293 Wogeck Oct. 31, 1939 2,311,234 Krajnc Feb. 16,1943 2,338,001 LaVigne Dec. 28, 1943 2,355,585 Halstead Aug. 8, 1944FOREIGN PATENTS Number Country Date 122,479 Great Britain Jan. 24, 1919560,261 Germany Sept. 30, 1932

